POS0103 PAIN AND FUNCTIONAL IMPAIRMENT ARE MORE PROMINENT IN EROSIVE HAND OSTEOARTHRITIS THAN IN TREATED RHEUMATOID ARTHRITIS: A COMPARATIVE STUDY BETWEEN DIGICOD AND ESPOIR COHORTS
Authors: S. Berkani, A. Aparicio Monforte, S. Tuffet, A. Rousseau, N. Rincheval, E. Maheu, B. Combe, A. Saraux, B. Fautrel, L. Gossec, F. Berenbaum, J. Sellam, A. Courties
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> The common belief is to consider hand osteoarthritis (HOA) as a less severe disease with a better functional prognosis and a lower global burden than rheumatoid arthritis (RA). However, this paradigm may no longer be true considering the striking efficacy of targeted therapies in RA compared to the weak efficacy of therapies in the most severe form of HOA, namely erosive HOA (EHOA), which impacts 10-20% of symptomatic HOA [1]. Few studies addressed this issue [2]. <h3>Objectives</h3> We aimed to compare the burdens of established EHOA and RA. The objectives were to compare pain, functional impairment, quality of life and the prevalence of comorbidities and of cardiovascular diseases (CVD) between established EHOA and RA. <h3>Methods</h3> DIGital Cohort Osteoarthritis Design (DIGICOD) is a French cohort of symptomatic HOA (at least 2 painful joints) with at baseline a mean ± SD disease duration of 12.9 ± 9.6 years [3]. This study involved the EHOA patients, from inclusion visit of DIGICOD, defined by at least 1 erosive joint according to the Verbruggen score. RA patients fulfilling ACR/EULAR 2010 criteria at the 10th year visit were selected from the ESPOIR cohort (Étude et Suivi des Polyarthrites Indifférenciées Récentes), a French cohort of early RA [4]. Pain intensity at rest or mobilization (0-100mm visual analogical scale (VAS)≥40/100), fatigue (VAS fatigue≥25/100), function (normalized (0-100) scores of Health assessment questionnaire for RA, and AUStralian CANadian Osteoarthritis Hand Index for EHOA &gt; 16.7) were analyzed and compared between EHOA and RA using logistic regression models adjusted on age, gender, BMI, comorbidities and socio-educational level. The risk to have ≥2 comorbidities (among CVD, cancer, hemopathy, fracture) or at least 1 CVD (among high blood pressure, diabetes, dyslipidemia, myocardial infarction, stroke) were compared between EHOA and RA adjusted on age, gender, BMI and socio-educational level. Odds ratios (OR) and their 95% confidence intervals (CIs) were reported (EOHA versus RA). <h3>Results</h3> We analyzed 138 patients with EHOA and 379 with RA. The median [interquartile] age of EHOA patients was higher than RA patients (67.3 [64.3; 72.2] vs 48.6 [39.9; 55.6] years, p&lt;0.001). The disease duration, at the evaluation time, was 13.5 [7.0; 20.0] for EHOA and 10.5 years [10.3; 10.7] for RA patients. RA was anti-CCP antibodies positive for 56% of patients and in remission for 61% (DAS28 &lt; 2.6). RA patients were treated by methotrexate (82%), biologics (37%) and 25% by corticosteroids while 20% of EHOA patients received oral non-steroidal anti-inflammatory drugs. EHOA patients had more painful joints in the hands than RA patients (4.0 [2.0;8.8] vs 0.0 [0.0;3.0], p&lt; 0.001). In the adjusted analysis, EHOA was associated with more pain at mobilization (OR = 3.13 95% CI [1.74 to 5.68] p&lt; 0.001) and more functional impairment (OR = 2.27 CI 95% [1.26 to4.17], p = 0.007) (Figure 1). There was no difference for pain at rest and for fatigue VAS. For comorbidities, the proportions of EHOA patients with ≥2 comorbidities were higher than RA patients (37.7% vs 27.5%). However, when we stratified by age, the proportions of patients with ≥2 comorbidities were higher in RA patients between 50 and 70 years old (30.2% vs 47.1%) compared to EHOA patients. In adjusted analysis, the risk to have ≥2 comorbidities was lower in EHOA than in RA patients (OR = 0.25 CI 95% [0.13 to0.48]; p&lt; 0.001) while there was no difference for CVD risk. <h3>Conclusion</h3> After more than 10 years of disease duration, EHOA is associated with more pain and more functional impairment but less comorbidities than RA. This study highlights the significant unmet need for effective therapies for patients with EHOA. <h3>References</h3> [1]Kwok WY et al., Ann Rheum Dis., 2011 [2]Slatkowky-Christensen B, Arthritis Rheum., 2007 [3]Sellam J., Joint Bone Spine, 2021 [4]Combe B., Rheumatology (Oxford),2021 <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None Declared.